Checklist of decapod crustaceans from the coast of the São Paulo state (Brazil) supported by integrative molecular and morphological data: III. Infraorder Brachyura Latreille, 1802.

This checklist is the third part of a series derived from a long-term multidisciplinary project on the biodiversity of decapod crustaceans from marine and coastal environments of São Paulo state (Brazil). We integrated molecular techniques (DNA markers) and morphological analyses of adult specimens for accurate identifications. We compilated 185 species from the literature, but we confirmed the presence of 168 species: 130 of which we sampled, analyzed and obtained sequences (COI and/or 16S totalizing 113 sequences) and 38 that were not directly collected but were confirmed by analyses. In addition, 27 had their distribution removed from São Paulo due to uncertainties, and absence of material as voucher. Five species were reported for the first time on the coast of São Paulo (Calappa ocellata, Neohelice granulata, Teleophrys pococki, Teramnonotus monodi, Tetraxanthus rathbunae) and one on the Brazilian coast (Pseudomedaeus agassizi). Most of the non-sampled species previously reported on the coast of São Paulo might be considered doubtful records stablished in the past by inaccurate analyses, which assumed extended distribution to the area and/or misidentifications. At this time and based on our refined compilation, we can estimate the brachyuran diversity on the coast of São Paulo in 168 species. This detailed inventory contributes to the knowledge on the local decapod fauna by checking available dataset, adding new species records in São Paulo and new sequences to GenBank database. These data may serve as baseline for future identifications and studies on conservation, population genetics, biogeography and phylogenetics, which might flag species that deserve further investigations and concerns.

DNA sequence database as a tool to identify decapod crustaceans on the São Paulo coastline.

DNA barcoding has emerged as an efficient tool for taxonomy and other biodiversity fields. The vast and speciose group of decapod crustaceans is not an exception in the current scenario and comparing short DNA fragments has enabled researchers to overcome some taxonomic impediments to help broadening knowledge on the diversity of this group of crustaceans. Brazil is considered as an important area in terms of global marine biodiversity and some regions stand out in terms of decapod fauna, such as the São Paulo coastline. Thus, the aim of this study is to obtain sequences of the mitochondrial markers (COI and 16S) for decapod crustaceans distributed at the São Paulo coastline and to test the accuracy of these markers for species identification from this region by comparing our sequences to those already present in the GenBank database. We sampled along almost the 300 km of the São Paulo coastline from estuaries to offshore islands during the development of a multidisciplinary research project that took place for 5 years. All the species were processed to obtain the DNA sequences. The diversity of the decapod fauna on the São Paulo coastline comprises at least 404 species. We were able to collect 256 of those species and sequence of at least one of the target genes from 221. By testing the accuracy of these two DNA markers as a tool for identification, we were able to check our own identifications, including new records in GenBank, spot potential mistakes in GenBank, and detect potential new species.

Taxonomic and Biogeographical Status of Three Species of the Spider Crabs of the Genus Acanthonyx Latreille, 1828 (Majoidea: Epialtidae) as Determined by DNA Barcoding and Morphological Analyses Along the Western Atlantic.

Ana Francisca Tamburus and Fernando Luis Mantelatto (2016) The genus Acanthonyx Latreille, 1828 contains 17 valid species, including A. dissimulatus Coelho, 1993, A. petiverii H. Milne Edwards, 1834 and A. scutiformis (Dana, 1851), which occur along the Brazilian coast. The high degree of intraspecific variation in the angle of hepatic region, size of the tubercles of the carapace and length of setae on the carapace and pereopods has resulted in difficulties with the taxonomy of this genus. Analysis of more consistent morphological and molecular characters are required to clarify the status of the three species that occurs in Brazil. For the molecular data, we used the barcode region of the mitochondrial gene COI as a marker, and we correlated this with morphological characters of adults and juveniles. The three species of Acanthonyx were morphologically similar and the matrix of genetic distances and maximum likelihood trees showed that A. dissimulatus and A. scutiformis belonged to the same group with A. petiverii. They could not be separated using the diagnosing characters proposed in the original description or genetically (present study), thus indicating that the taxonomic status of the first two species is questionable. The division into two distinct groups corresponding to A (Caribbean, Brazil, Venezuela) and B (USA, Mexico) was well supported and indicated that there are genetic differences between these populations. Present study suggests the existence of a single species in Brazil and Caribbean, assigned to A. petiverii (type locality in Antilles). The existence of a new species restricted to North America confirms the cryptic diversity within Acanthonyx.